GlcNAc is a pharmaceutically and nutraceutically useful compound, which was widely used for treatment of osteoarthritis and maintaining health of the joint. Previously a Bacillus subtilis strain has been constructed for efficient production of GlcNAc. However, low GlcNAc titer in industrial relevant fermentation medium of engineered B. subtilis restricts the application for industrial production. To move a step forward for microbial GlcNAc fermentation in industrial conditions, yield and GlcNAc titer should be enhanced. The glmS ribozyme can cleave the messenger RNA of the glmS gene in Gram-positive bacteria. It is activated by glucosamine-6-phosphate (GlcN6P) which is the metabolic product of the GlmS enzyme to stimulate autocatalytic site-specific cleavage. The metabolite-induced self-cleavage specifically targets the downstream transcript for intracellular degradation. This degradation pathway relies on action of Rnase J1. Rnase J1 specifically degrades products with a 5′ hydroxyl terminal arisen from site-specific cleavage. And the ribozyme serves as a metabolite-responsive genetic switch that represses the glmS gene in response to rising glucosamine-6-phosphate (GlcN6P) concentrations. GlcNAc related biosynthesis was divided into modules including into the GlcNAc synthesis module, pentose phosphate pathway (PPP) module, glycolysis module, and peptidoglycan synthesis module. The GlcNAc synthesis module, peptidoglycan synthesis module, glycolysis module and pentose phosphate pathway module compete for the same precursors. Therefore, the competitive glycolysis and peptidoglycan synthesis modules should be downregulated and the GlcNAc synthesis module should be upregulated for GlcNAc synthesis. As implied above, most methods for metabolic engineering (esp. in B. subtilis) impart an inherently static control of gene expression, and thus result in undesirable and unbalanced metabolic flux distributions. As a result, titers are often limited due to toxic intermediates and metabolic imbalances.